Slitting attachment for calenders



March 17, 1936. H. D. STEVENS V SLITTING ATTACHMENT FOR CALENDERS Filed July 14, 1933 2 Sheets-Sheet 1 n INVENTOR D. Jrevavs ATTORNEYS March 17, 1936. H D TEVEN 2,034,641

SLITTING ATTACHMENT FOR CALENDERS Filed July 14, 1933 2' sheets sheet 2 INVEN OR 144mm; 0. 70m:

ATTORNEYS Patented Mar. 17, 1936 UNITED STATES PATENT OFFIE SLITTING ATTACHIVIENT FOR CALENDERS Application July 14, 1933, Serial No. 680,412

9 Claims.

This invention relates to slitting attachments for calenders, and more especially it relates to slitting attachments for rubber-sheeting calenders wherein a multiplicity of slitter knives are mounted in engagement with the surface of a calender roll for cutting relatively narrow strips from a sheet of unvulcanized rubber composition thereon.

The chief objects of the invention are to provide an improved slitter knife for the purpose mentioned; to provide an improved means for supporting a multiplicity of such slitter knives; and to provide improved means for yieldingly urging the slitter knives against a calender roll.

More specifically, the invention aims to provide slitter knives that require to be sharpened less frequently than slitter knives heretofore provided; that may be sharpened easily and quickly; and to provide a knife and knife-holding structure that may be disposed alternatively in different relationship whereby relatively small adjustment of knife-spacings may be effected. A further object is to provide for easily, quickly and accurately altering the lateral spacings of a series of slitter knives. Other objects will be manifest.

Of the accompanying drawings:

Figure 1 is a plan view of a portion of a calender roll, and the improved slitting attachment associated therewith, in operative position;

Figure 2 is a front elevation of the mechanism shown in Figure 1;

Figure 3 is a section on the line 33 of Figure 1, on a larger scale;

Figure 4 is rear elevation, on a larger scale, of a portion of the mechanism shown in Figure 1, as indicated by the line 44 thereof;

Figure 5 is a section on the line 5-5 of Figure 1, on a larger scale;

Figure 6 is a section on the line 6-6 of Figure 3, showing the knives in elevation and in an alternative arrangement to eifect a different lateral spacing;

Figure '7 is a plan view of a knife-setting gauge or jig as it appears in operative association with a knife holder; and

Figure 8 is a diagrammatic vertical sectional view, on a reduced scale, of a rubber-working calender and the improved slitting attachment mounted thereon.

Referring first to Figure 8 of the drawings, there is shown a three-roll calender comprising a pair of frame members such as the end-frame I0, and upper, middle and lower rolls H, I2, and

l3 respectively. A sheet of unvulcanized rubber composition I 4 is formed on the calender roll l2 from a bank I5 of such composition fed into the bite of rolls ll, l2, and the improved slitting attachment, generally designated S, is mounted 5 upon the calender in association with roll 12 for slitting the sheet l4 thereon intoa plurality of strips. The slitted sheet passes between rolls l2, l3, which rolls preferably. are not in contact with each other, and at the rear of the calender the 10' rubber strips are withdrawn from the calender roll l2 and reeled into a roll l6 with a liner H, the latter being withdrawn from an adjacent liner-roll IS. The strips that are reeled up are in spaced relation to each other, the material 15 from between said strips remaining on the roll l2 and passing back into the bank of stock I 5.

Referring now to the other figures of the drawings, the slitting attachment S comprises a main knife support consisting of a Z-bar 20 that is 20 positioned at the front of the calender adjacent and parallel to the roll 12, said support being carried by a pair of brackets 2|, 2! mounted upon the respective calender frames H]. To give lateral rigidity to the main support, it is constructed as 25 a truss, there being tie-rods 22, 23 connected to the respective ends of the Z-bar 20 and a rearwardly extending brace 24 secured the middle thereof, the tie-rod 22 extending around the outer margin of said brace, and the adjacent ends 30 of the tie-rods being drawn together by a turnbuckle 25.

The support 20 is so arranged that the leg on its lower margin extends horizontally toward the calender roll l2, and formed on the upper face 35 of said leg is a longitudinal series of spaced bosses 21, 21. Adjacent each end of the bar 20 and at determinate intermediate points, respective webs 28, 28 are welded in place, said webs being apertured to receive and retain a cylindrical 40 rocker rod 29, the intermediate portions of said rod, between said webs, resting upon the bosses 21. The rod 29 supports a plurality of knife holders 3!], herein shown as three in number, which are arranged for limited rocking movement 45 on said rod.

Each knife holder 30 comprises an elongate metal bar that is rectangular in section, and has its face that is adjacent roll l2 formed with a multiplicity of knife-receiving slots 32, 32, said slots 50 being substantially inch wide and spaced inch laterally of each other. A plate 33 is secured to the slotted face of the knife holder 30 to close the open margins of said slots. Secured to the bottom of the knife holder is a rocker bar 55 34 that closes the lower ends of slots 32, the upper face of said rocker bar preferably being formed with a longitudinal groove 35 in the portion thereof disposed below said slots, as is shown in Figure 3, for a purpose presently to be explained. Along its bottom face, directly below slots 32, the rocker bar 34 is formed with a spaced series of lugs 36, 36 that are slotted to fit over rod 29, said lugs thus constituting bearings for the knife holder. Since the lugs 36 are disposed nearest to that side of the knife holder that faces the roll l2, the knife holder normally is inclined to tilt rearwardiy, away from said roll, as indicated in broken lines in Figure 3. The top face of each knife holder may be formed with two recesses 31, 31 traversed by respective pins 38 whereby the knife holder may be engaged by a pair of grab hooks or tongs,:shownin broken lines at 39, Figure 2, for lifting the said holder into and out of its seat on the rod 29 upon occasion, as when repositioning the knives carried by said holder.

The slitter knives used with this invention each comprise a handle 4|, and :a blade 42 adjustable relatively thereof. The blade 42 is a circular metal disc that has asharp edge formed by a-single peripheral bevel. It is secured to one end of the handle M :by an :axial cap-screw 43, and is formed with a circular series of apertures 44, 44, herein shown as eight in number, concentric with cap-screw 4.3.. The handle 4| is provided with a laterally projecting stud or dowel #5, Figure 4, that is received alternatively in the apertures 44 when the cap screw 43 is loosened. The arrangement is such that the blade 42 may be angularly adjusted on the handle M to bring various regions of its perimeter into position to be urged against the roll l2 to slit the work thereon, the blade normally being in fixed position on its handle.

The handle 4| of each slitter knife is substantially the same thickness as the width of each knife-holder-slot 32, so as to ibe'incapable of any lateral movement when mounted in said slots. The breadth of each knife handle 4| is somewhat less than the transverse depth of the slots 32,'permitting a small amount of rocking movement of the handle between the plate 33 and the rear of the slots. The lower end of the handle 4| is bluntly pointed as shown at 48, Figure 3, and said point rests in the bottom of groove 35 of rocker bar 34, thus providing a single point of support for the handle 41 upon which said handle may rock edgewise relatively of the knife holder 30 and relatively of the other knife handles. The arrangement is such that all the knives mounted in a single knife holder .30 may be yieldingly urged against the calender :roll 12 with uniform pressure by a single instrumentality, notwithstanding varying degrees of wear of the several knives or other inequities in their respective structures.

For yieldingly urging all the knives of a single knife holder 30 against the calender roll I2 there is provided an elongate resilient cushion 48 of rubber or similar material, which cushion is mounted upon one margin of a presser bar 49 that is mounted upon a slide 58 that is movable transversely of the upper face of the top leg of the main support 20, toward and away from the roll i2. The freeedge of the cushion 48 abuts one margin of the knife handles 4| whereby the knives may be yieldingly urged against roll l2. The slide 58 is slidably mounted upon the support 20 in undercut lateral guides 51, .51 which carry upon their end portions remote from roll l2, a screw bearing 52 through which is threaded a screw 53 that has one of its ends swiveled centrally in the presser bar 49, the other end of said screw being provided with a hand wheel 54 by which said screw is manually rotated to reciprocate said presser bar.

In the operation of the slitter, moving of the cushion 48 toward the roll |.2 yieldingly urges all of the knives 42 thereagainst with uniform pressure due to the feature of having the knife handles movable relatively of each other in an edgewise direction. Moving of the cushion 48 away from the knife handles withdraws all the knives from the roll "|2 by permitting the knife holder 30 to assume its normal tilted position on the rod 29, as indicated in broken lines in Figure 3. When the cushion 48 is completely retracted, the top of the knife holder 30 is unobstructed, and the knife holder may be lifted from its seat on the rod 29, by means of the tongs 39, and deposited at any convenient place for the repositioning, removal, adjustment or substitution of the knives.

For convenience, the knives may be mounted in the knife holder 38 with the aid of a gauge plate or jig 5B, Figure 7, which jig has one margin formed with shallow slots 58, 58 that are laterally spaced according to width of the strips to be slit on the roll l2. The slots '58 are so arranged that the jig may be superposed upon the knife support 38 and said slots 58 registered with slots 32 in said knife support. The slitting knives may then be easily and quickly mounted in those slots 32 that are in registry with slots 58 of the jig. To assure accurate positioning of the jig on the knife support 30, the latter may have dowels 59, 59' projecting from its top face, and the jig may be formed with complementally disposed apertures 68 to receive said dowels. Any number of jigs may be provided according to the various widths of stock to be slit.

The feature of having the knife blade 42 angularly adjustable upon its handle 4| avoids the necessity of frequently sharpening the blade, and by providing a blade in the form of a disc the sharpening thereof is facilitated since it requires only to rotate it against a suitable abrading element. The feature of providing a cutting edge on the blade by means of a single bevel on its perimeter makes it possible to alter the position of the cutting edge with relation to the handle 4| a distance equal to the thickness of the blade simply by reversing the position of the blade on the handle, that is, by placing its opposite face in contact with the handle. It is also possible to vary the spacing between the cutting edges of the blades 42 a distance equal to the thickness of the handles 4| simply by reversing a handle with relation to its adjacent handle, as will be apparent from a comparison of the blade-spacings of Figures 5 and 8, the distance between handles in both figures being the same.

The setting and resetting of the slitter knives is easily, quickly and accurately accomplished even with unskilled labor. The device is capable of relatively nice adjustment for the cutting of strips of various widths, and it achieves the several advantages set out in the foregoing statement of objects.

Modification may be resorted to without departing from the spirit of the invention or the scope of the appended claims, which are not limited wholly to the specific construction shown and described.

What is claimed is:

1. A slitting attachment for calenders comprising a disc-knife, a handle therefor, and yielding means engaging said handle for urging the knife against a calender roll, said handle being so disposed as to move the knife away from said roll by gravity when said yielding means is withdrawn.

2. A slitting attachment for calenders comprising a knife support that is pivotally mounted near one side thereof, a plurality of handles hav ing knife blades on one end thereof mounted in said support, and yielding means rocking said knife support and moving the knife blades into engagement with a calender roll, said support withdrawing said blades from said calender roll by gravity when said yielding means is withdrawn.

3. A slitting attachment for calenders comprising a plurality of handles having knife blades on one end thereof, a knife support for said handles, a pivotal mounting for said knife support from which said support may be freely lifted, and means for rocking said knife support and for moving the knife blades in unison into engagement with a calender roll.

4. A slitting attachment for calenders comprising a pivotally mounted knife support formed with a plurality of slots, slitter knives having handles receivable in said slots, said handles so fitting said slots as to be laterally rigid therein and to have limited edgewise movement relatively of the support, and means engaging said handles adapted to rock the support and to move the knives into engagement with a calender roll.

5. A slitting attachment for calenders comprising a pivotally mounted knife support, slitter knives having handles carried by said support, a resilient cushion, and manually operated means for moving the cushion into and out of engagement with the knife handles to rock the knife support and move the knives into and out of engagement with a calender roll.

6. A slitting attachment for calenders comprising a pivotally mounted knife support formed with a plurality of slots, the bottoms of which are transversely grooved, slitter knives having handles receivable in said slots, the lower ends of said handles being bluntly pointed to enter said grooves in the slots, the slots being of greater transverse depth than the breadth of the knife handles permitting limited rocking movement of the said handles, on their pointed ends, relatively of the knife support, and yielding means engaging said knife handles to rock the support and urge the knife blades into engagement with a calender roll.

7. A slitting attachment for calenders comprising a main frame, a rocker rod carried thereby, a plurality of knife supports freely resting upon said rocker rod and adapted to pivot thereon, a plurality of slitter knives carried by said knife supports, and respective yielding means associated with the knife supports for urging the knives carried thereby yieldingly against a calender roll.

8. A slitting attachment for calenders comprising a plurality of disc-knives, respective handles disposed radially of the blades to which said blades are non-rotatably secured, a knife support formed with a plurality of closely spaced slots for receiving the knife handles, the latter having limited, edgewise, pivotal movement in said slots, relatively of said support, a rocker bar upon which said knife support freely rests and about which it pivots, a resilient cushion bearing against all the knife handles, and means for manipulating said cushion to urge the knives toward a calender roll.

9. In a device of the character described, the combination of a knife support formed with a plurality of closely adjacent slots, slitter knives having handles receivable in said slots, and a jig bar having determinedly spaced marginal slots, which slots are registerable with certain of the slots in the knife support to facilitate the mounting of the knife handles therein.

HORACE D. STEVENS. 

